#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef long double ld;
typedef pair<ll,ll> pl;
typedef pair<int,int> pii;
typedef tuple<int,int,int> tpl;
#define all(a) a.begin(), a.end()
#define filter(a) a.erase(unique(all(a)), a.end())
const int mn = 1e5 + 5, Q = 3e5 + 5;
vector<pl> nxt[18][mn], flight[mn], qry[mn];
vector<int> ord[mn];
ll ans[Q], n, T;
ll travel (int node, int flightID, int step) {
ll ans = 0;
for (int i = 0; step; step >>= 1, i++) {
if ((step & 1) == 0) continue;
ll weight; tie(flightID, weight) = nxt[i][node][flightID];
ans += weight, node += (1 << i);
}
return ans;
}
int main()
{
ios::sync_with_stdio(0);
cin.tie(0);
// read flights info
cin >> n >> T;
for (int i = 1; i < n; i++) {
int m; cin >> m;
flight[i].resize(m);
for (int j = 0; j < m; j++) {
int a, b; cin >> a >> b;
flight[i][j] = {a, b};
}
sort(all(flight[i]));
}
// resize + setup stuffs
for (int i = 1; i < n; i++) {
ord[i].resize(flight[i].size());
for (int s = 0; s < 18; s++)
nxt[s][i].resize(flight[i].size());
for (int j = 0; j < ord[i].size(); j++) ord[i][j] = j;
sort(all(ord[i]), [&] (int a, int b)
{ return flight[i][a].second > flight[i][b].second; });
}
// build edge
for (int i = 1; i + 1 < n; i++) {
int iter = flight[i + 1].size(), best = INT_MAX, idx = -1;
int soonest = min_element(all(flight[i + 1]), [&] (pii a, pii b) { return a.second < b.second; } ) - flight[i + 1].begin();
for (int u : ord[i]) {
// calculate transition for nxt[i][u]
while (iter - 1 >= 0 && flight[i][u].second <= flight[i + 1][iter - 1].first) {
int cur = flight[i + 1][--iter].second;
if (cur < best) best = cur, idx = iter;
}
if (idx == -1) { // wait overnight and take the `soonest` flight
// cout << "state " << i << " " << u << "\n";
ll link = soonest, weight = T - flight[i][u].second + flight[i + 1][soonest].second;
nxt[0][i][u] = {link, weight};
}
else { // take the `best` flight to fly in the same day
ll link = idx, weight = flight[i + 1][idx].second - flight[i][u].second;
nxt[0][i][u] = {link, weight};
}
int link, weight; tie(link, weight) = nxt[0][i][u];
// cout << "(" << i << ", " << u << ") -> (" << i + 1 << ", " << link << "), weight " << weight << "\n";
}
}
// binary-lifting pre-processing
for (int s = 1; s < 18; s++) {
for (int i = 1; i + (1 << s) < n; i++) {
for (int j = 0; j < flight[i].size(); j++) {
ll link, weight; tie(link, weight) = nxt[s - 1][i][j];
ll nxtLink, nxtWeight; tie(nxtLink, nxtWeight) = nxt[s - 1][i + (1 << (s - 1))][link];
nxt[s][i][j] = {nxtLink, weight + nxtWeight};
}
}
}
// read queries
int q; cin >> q;
for (int i = 0; i < q; i++) {
int l, r; cin >> l >> r;
qry[l].emplace_back(r, i);
}
// process queries
for (int i = 1; i < n; i++) {
if (qry[i].empty()) continue;
sort(all(qry[i]));
function<ll(int,int)> tryFlight = [&] (int flightID, int destination) {
int step = destination - i - 1;
return travel(i, flightID, step) + flight[i][flightID].second - flight[i][flightID].first;
};
for (auto [r, idx] : qry[i]) {
ans[idx] = LLONG_MAX;
for (int u : ord[i]) ans[idx] = min(ans[idx], tryFlight(u, r));
}
// function<void(int,int,int,int)> solve = [&] (int a, int b, int optL, int optR) {
// if (i == 2) {
// cout << "solve {";
// for (int jj = a; jj <= b; jj++) cout << qry[i][jj].second << " ";
// cout << "}, ";
// cout << optL << ".." << optR << "\n";
// }
//
// if (optL == optR) {
// for (int it = a; it <= b; it++) {
// int r, idx; tie(r, idx) = qry[i][it];
// ans[idx] = tryFlight(ord[i][optL], r);
// }
// return;
// }
// int mid = (a + b) >> 1, bestID = -1;
// ll best = LLONG_MAX;
//
// int r, idx; tie(r, idx) = qry[i][mid];
// for (int tryID = optL; tryID <= optR; tryID++) {
// if (i == 2 && idx == 2) {
// cout << "wth " << ord[i][tryID] << " " << tryFlight(ord[i][tryID], r) << "\n";
// cout << "bruh " << i << " " << r << " " << travel(i, ord[i][tryID], r - i - 1) << "\n";
// }
// ll cur = tryFlight(ord[i][tryID], r);
// if (cur < best) best = cur, bestID = tryID;
// }
// ans[idx] = best;
// if (a < mid) solve(a, mid - 1, optL, bestID);
// if (mid < b) solve(mid + 1, b, bestID, optR);
// };
// solve(0, qry[i].size() - 1, 0, ord[i].size() - 1);
// for (pii item : qry[i]) {
// int r, idx; tie(r, idx) = item;
//
// res = (iter == -1 ? LLONG_MAX : travel(i, ord[i][iter], r - i - 1) + flight[i][ord[i][iter]].second - flight[i][ord[i][iter]].first);
// while (iter + 1 < ord[i].size()) {
// int u = ord[i][iter + 1];
// ll tryFinish = travel(i, u, r - i - 1) + flight[i][u].second - flight[i][u].first;
// if (i == 3) cout << "bruh " << idx << " " << travel(i, u, r - i - 1) << " " << r - i - 1 << " " << u << "\n";
// if (tryFinish < res) res = tryFinish, iter++;
// else break;
//// cout << "jump " << i << " " << u << " " << r - i - 1 << "-step " << res << "\n";
// }
// ans[idx] = res;
// }
}
// print output
for (int i = 0; i < q; i++) cout << ans[i] << "\n";
return 0;
}
